I understood from the K&N site that they recommend not over-oiling the filters because, on those cars which use electronic fuel injection, the
oil may coat and foul some of the intake air sensors of the EFI system. It seems to me that those of us using carbs should have little to worry about in that regard, but that's a relatively uneducated guess.
One thing I am curious about, however. I took off my (2) filters and cleaned them last weekend. Despite using the entire bottle of cleaner and washing each out thoroughly three times, I could not get them to return to any semblance of white color. The best I could get was a dark grey, almost black. They seem clean and on the third attempt I got no more crud out of the filters, but they are black and won't come any whiter. I don't really care about the color except it's harder to get the
oil on evenly when you can't see where it's going. Their website says don't do anything except use their detergent, and especially warns against using chlorine bleach. Anybody got any suggestions?